title: Inhibitory effects of gallic acid and quercetin on UDP-glucose dehydrogenase activity.
abstract: We have examined polyphenols as potential inhibitors of UDP-glucose dehydrogenase (UGDH) activity. Gallic acid and quercetin decreased specific activities of UGDH and inhibited the proliferation of MCF-7 human breast cancer cells. Western blot analysis showed that gallic acid and quercetin did not affect UGDH protein expression, suggesting that UGDH activity is inhibited by polyphenols at the post-translational level. Kinetics studies using human UGDH revealed that gallic acid was a non-competitive inhibitor with respect to UDP-glucose and NAD+. In contrast, quercetin showed a competitive inhibition and a mixed-type inhibition with respect to UDP-glucose and NAD+, respectively. These results indicate that gallic acid and quercetin are effective inhibitors of UGDH that exert strong antiproliferative activity in breast cancer cells.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Hwang
authors.forename: Jae-Wan
authors.initials: JW
authors.lastname: Huh
authors.forename: Myung-Min
authors.initials: MM
authors.lastname: Choi
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Choi
authors.forename: Hea-Nam
authors.initials: HN
authors.lastname: Hong
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Cho
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005707:Gallic Acid / Q000494:pharmacology*; D006801:Humans; D009243:NAD / Q000494:pharmacology; D011794:Quercetin / Q000494:pharmacology*; D014532:Uridine Diphosphate Glucose / Q000494:pharmacology; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D009243:NAD; D005707:Gallic Acid; D011794:Quercetin; D014533:Uridine Diphosphate Glucose Dehydrogenase; D014532:Uridine Diphosphate Glucose